1. Field of the Invention
The present invention relates to an organic light emitting display panel, and more particularly, to an organic light emitting display panel in which an arrangement structure of sub-pixels is changed to widen a width of an organic emission layer.
2. Discussion of the Related Art
A flat panel display (FPD) device is applied to various electronic devices such as portable phones, tablet personal computers (PCs), notebook computers, monitors, etc. Examples of the FPD device include liquid crystal display (LCD) devices, plasma display panel (PDP) devices, organic light emitting display devices, etc. Recently, electrophoretic display (EPD) devices are being widely used as one type of the FPD device.
Among the display devices, the organic light emitting display devices use a self-emitting element, and thus have a fast response time, high emission efficiency, high luminance, and a broad viewing angle.
The organic light emitting display devices may be configured in a top emission type where an organic light emitting diode (OLED) is formed on a lower substrate, and light emitted from the OLED is output to the outside through an upper substrate.
Moreover, the organic light emitting display devices may be configured in a bottom emission type where the OLED is formed on the lower substrate, and the light emitted from the OLED is transferred to the lower substrate.
Recently, organic light emitting display devices that emits light in a dual emission type where the bottom emission type is combined with the top emission type are being developed.
FIG. 1 is a first exemplary diagram illustrating a related art organic light emitting display panel 10, and particularly, is an exemplary diagram illustrating an organic light emitting display device in which a plurality of sub-pixels are arranged in a stripe structure.
A plurality of sub-pixels 11 applied to the related art organic light emitting display panel 10, as illustrated in FIG. 1, are arranged in the stripe structure.
A plurality of contact holes (PLN Hole) 13 illustrated in FIG. 1 may be formed in the organic light emitting display panel 10 so that a driving transistor, e.g., a driving thin film transistor (TFT), used to drive an OLED 12 is electrically connected to the OLED 12.
For example, the driving TFT (not shown) is insulated from the OLED 12 by an insulation layer (not shown). Therefore, the contact hole 13 may be formed on the insulation layer so that the driving TFT and the OLED 12 separated from each other by the insulation layer are electrically connected.
In this case, as illustrated in FIG. 1, the contact holes 13 are respectively formed at the same positions of lower ends of all the sub-pixels 11.
In the related art organic light emitting display panel 10, since the contact holes are respectively formed at the same positions of the lower ends of the sub-pixels 11, enhancement of an aperture ratio is limited when the sub-pixels 11 are formed by using a fine metal mask (FMM). That is, since each of the contact holes 13 is disposed adjacent to a boundary between adjacent sub-pixels, an emission area of each sub-pixel is reduced. Also, the fine metal mask has a pattern so as to correspond to one sub-pixel, and it is required to manufacture a smaller pattern when manufacturing a high-resolution organic light emitting display panel. However, there is a limitation in manufacturing a smaller pattern. The fine metal mask is a mask that is used to deposit an organic emission layer in units of a pixel in an organic light emitting display panel, and has a fine pattern. Therefore, the pattern of the fine metal mask should be further reduced in the high-resolution organic light emitting display panel, and for this reason, it is difficult to form a structure of the sub-pixels illustrated in FIG. 1. For example, in an organic light emitting display panel having a high resolution of 300 ppi or more, it is difficult to form the structure of the sub-pixels illustrated in FIG. 1.
That is, a resolution of organic light emitting display panels becomes increasingly higher, but due to the above-described structure of the sub-pixels of the related art, it is difficult to manufacture the high-resolution organic light emitting display panel.
To provide an additional description, as the resolution of an organic light emitting display panel increases, a size of a sub-pixel is reduced. In this case, the thickness of the fine metal mask used to manufacture the organic light emitting display panel is limited, and since a distance between ribs of the fine metal mask is insufficient, a desired aperture ratio cannot be realized in the organic light emitting display panel using the structure of sub-pixels of the related art. That is, in the process of evaporating an organic emission layer by using an evaporation process, due to a limitation of a method of manufacturing the fine metal mask, it is difficult to manufacture an organic light emitting display panel having a high resolution.